Will Constant Power on 12 Volt Circuit After ETBC7 Installation Drain Vehicle Battery

Question:

The instructions for wiring a 7 prong trailer plug indicate that the hot wire to charge the trailer battery should be connected through a circuit breaker directly to the positive terminal on the vehicle battery, but wouldnt this provide the potential for draining the vehicle battery if left plugged in while camping? Is there a place to wire to that only has power when the vehicle key is on? Vehicle is 2000 Chevy Venture Thanks!

asked by: James M

Expert Reply:

Yes, after installing # ETBC7 you will have constant power on that circuit. The easiest solution is to just unplug the trailer from the vehicle. Having power at the connector without it going anywhere will not drain the vehicle battery.

If you don't want to unplug the trailer every time you can easily add a battery isolator like # PK5231201. On the power wire, instead of running from the BAT post on the circuit breaker to the battery, you will run it to the output side of the isolator. Then the input side of the isolator will run to the positive battery terminal. And the center post would need to connect to a power source that is only hot when the truck is running. This way if you turn off the truck it will cut the power to the 12 volt circuit.

expert reply by: Chris O